!7

concept Word {
  S text;
  long lastUsed;
}

p {
  db();
  botSleep("Word Holder.");
}

synchronized answer {
  if "list words" ret struct(wordsByLastUse());
  if "size" ret countConcepts(Word);
  if "add words *" { addWords((L) safeUnstruct($1)); ret "OK"; }
}

static L<S> wordsByLastUse() {
  ret collect(sortByFieldDesc(list(Word), "lastUsed"), "text");
}

// return number of new words
static int addWords(L<S> words) {
  long lastUsed = now();
  int n = 0;
  for (S text : words) {
    Pair<Word, Bool> p = uniq2(Word, +text);
    if (p.b) ++n;
    cset(p.a, +lastUsed);
  }
  ret n;
}